Energy And Exergy Assessment of North Refineries Company (NRC) Steam Cycle Based on Air Mass Flowrate of Main Condenser (original) (raw)
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Energy and exergy analysis of Montazeri Steam Power Plant in Iran
ScienceDirect, 2016
This paper aims at investigating steam cycle of Shahid Montazeri Power Plant of Isfahan with individual unit capacity of 200 MW. Using mass, energy, and exergy balance equations, all cycle equipment have been analyzed individually and energy efficiency, exergy efficiency, and irreversibility has been calculated for each of them as required. EES (Engineering Equation Solver) software is used for performing analyses. Values and ratios regarding heat drop and exergy loss have been presented for each equipment in individual tables. The results from the energy analysis show that 69.8% of the total lost energy in the cycle occurs in the condenser as the main equipment wasting energy, while exergy analysis introduces the boiler as the main equipment wasting exergy where 85.66% of the total exergy entering the cycle is lost.
Innovative Energy & Research, 2018
This study aims to conduct a performance evaluation of a 135 MW Circulating Fluidized Bed (CFB) Coal Based Thermal Power Plant using exergy analysis and use these assessments in order to provide an optimum operation of the said plant. The study includes on determining the effects of ambient condition on the exergy analysis of the plant. The necessary parameters such as temperature, pressure and mass flow rates were collected from the DCS (Distributed Control System) of the plant. These parameters are then inputted in the excel file prepared by the proponent in order to arrive at necessary thermodynamic values. The results in the exergy analysis of the plant showed that most of the exergy losses occur in the boiler with a total of 172222.8 kJ/s under low temperature ambient and 182602.3 kJ/s at high temperature ambient. The high exergy loss in boiler is caused by unutilized heat that was not fully transferred in to turbine cycle system and is just venter out in the atmosphere. Turbine cycle exergy only accounts to 5 to 6 percent of the total initial exergy available. Most of these exergy losses are located at IP/LP turbine (8564.64 kJ/s), condenser (4818.07 kJ/s), cold reheat pipe (4690.16 kJ/s), HP turbine (1697kJ/s) and Deaerator (1055.82 kJ/s). Moreover, based the exergetic efficiency, most of the components in the turbine cycle that involve phase change are most likely to have low efficiency these include the boiler (50.97%), condenser (42.68%), gland steam cooler (75.34%) and LPH no.7 (13.46%). The effect of ambient temperature on the generation of irreversibility in the plant is considerable. During high ambient temperatures, the boiler produces high irreversibility than that of the low ambient temperatures. However, if we look into the turbine cycle side, the most irrversibilities are seen during low ambient conditions which are around 6.54 percent whilst the hotter ambient condition poses only a tad lower value of 5.79 percent. The optimized parameter in maximizing the load is suggested on the results which are: Unit load = 40 MW and main steam temperature = 530 Mpa. Heat exchange between the component and the system is a significant part in the exergy analysis of the plant. Thus an exact approximation of the actual heat transfer would decently make the exergy analysis more accurate. Moreover, the program for thermodynamic value determination can be made from other programming platform aside from excel in order to create a faster generation of data and can be easily organize accordingly. Lastly based on the results provided by the exergy analysis on the plant, it recommended to formulate plans for improvements on plant components with high exergy loses especially the cold reheat pipe.
Exergy Analysis for Performance Optimization of a Steam Turbine Cycle
2007 IEEE Power Engineering Society Conference and Exposition in Africa - PowerAfrica, 2007
Exergy analysis of a 500 MWe steam turbine cycle is performed to identify the components that offer significant work potential saving opportunity. Criteria of performance relevant to the individual components are formulated. Exergy flows, exergy consumption due to irreversibilities and rational performance parameters for the turbine cycle and its components are computed by using plant operation data under different conditions. Energy efficiency of the turbine cycle is low due to large energy rejection, but the derived exergy efficiency of the turbine cycle is high due to low exergy rejection from the cycle. Part load operation exhibits lower energy efficiency due to higher energy rejection relative to net output. On the contrary, exergy rejection from the cycle relative to net output does not increase during low load operation. Results show that poor part load exergy efficiency is due to higher exergy destruction relative to net output. Higher pressure feed heaters deal with larger exergy and therefore, need more attention to improve cycle efficiency. Operation and maintenance decisions based on exergy analysis have proved to be more effective in reducing inefficiencies in operating power plant. Exergy-based approach of performance analysis will help practicing power engineers manage energy resources and environment better.
. 21-31 Steam Condenser Exergy Analysis of Steam Power Plant at Different Loads
NORTH AMERICAN ACADEMIC RESEARCH (NAAR) JOURNAL, 2021
This paper presents steam condenser exergy analysis of 50 MW unit of the power plant by varying the ambient temperature from 5 C to 42 C at different loads. The performance parameters and the dependent variables are the exergy entering in the condenser, exergy out from the condenser, exergy efficiency of the plant, exergy destruction in the condenser and the exergy efficiency of condenser. Whereas the independent variables are ambient temperature and condenser pressure. It was seen that increases of exergy efficiency of the plant depends on combined effect of ambient temperature and condenser pressure as the sole variation of ambient temperature doesn’t have much effect on the performance parameters. The varying of ambient temperature without altering the condenser pressure doesn’t have any significant impact but by varying simultaneously the ambient temperature along with the changing of condenser pressure has profound effect on the performance parameters. As the Condenser pressure increases the heat loss is also increasing which shows the major portion of energy loss occurs in condenser. In comparison of heat loss in condenser the exergy destruction in condenser is very less. At the optimal condenser pressure 0.00804 MPa the exergy efficiency of the whole unit, exergy destruction in condenser, exergy efficiency of condenser, Heat loss (Q) in condenser and Wtotal are as 26.26%, 198.1KW, 99.72%, 81190 KW and 53.4 MW respectively and the optimal condition is attained at the full load(100%) or designed operating parameters.
Energy and Exergy Analysis of a 348.5 MW Steam Power Plant
Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, 2010
In the present work, the energy and exergy analysis of Kostolac power plant in Serbia is presented. The primary objectives of this article are to analyze the system components separately and to identify and quantify the sites having the largest energy and exergy losses. The energy and exergy efficiency is calculated using the plant operating data from the plant at different loads. The load variation is studied with the data at 100% and 60% of full load. Moreover, the effects of the load variations are calculated in order to obtain a good insight into this analysis. The performance of the plant is estimated by a component-wise modeling, and a detailed break-up of energy and exergy losses for the considered plant has been presented. The results show that energy losses have mainly occurred in the condenser where 421 MW is lost to the environment while only 105.78 MW has been lost from the boiler. Nevertheless, the irreversibility rate of the boiler is higher than the irreversibility rates of the other components. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system (88.2%) followed by the turbines (9.5%), and then the forced draft fan condenser (0.5%). In addition, the calculated thermal efficiency based on the lower heating value of fuel was 39% while the exergy efficiency of the power cycle was 35.77%.
Energy and exergy analysis of a steam power plant in Jordan
In this study, the energy and exergy analysis of Al-Hussein power plant in Jordan is presented. The primary objectives of this paper are to analyze the system components separately and to identify and quantify the sites having largest energy and exergy losses. In addition, the effect of varying the reference environment state on this analysis will also be presented. The performance of the plant was estimated by a componentwise modeling and a detailed break-up of energy and exergy losses for the considered plant has been presented. Energy losses mainly occurred in the condenser where 134 MW is lost to the environment while only 13 MW was lost from the boiler system. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system (77%) followed by the turbine (13%), and then the forced draft fan condenser (9%). In addition, the calculated thermal efficiency based on the lower heating value of fuel was 26% while the exergy efficiency of the power cycle was 25%. For a moderate change in the reference environment state temperature, no drastic change was noticed in the performance of major components and the main conclusion remained the same; the boiler is the major source of irreversibilities in the power plant. Chemical reaction is the most significant source of exergy destruction in a boiler system which can be reduced by preheating the combustion air and reducing the air-fuel ratio.
Energy and Exergy Analysis of a Steam Power Plant in Sudan
African Journal of Engineering and Technology, 2021
In this study, the energy and exergy analysis of Garri 4 power plant in Sudan is presented. The primary objective of this paper is to identify the major source of irreversibilities in the cycle. The equipment of the power plant has been analyzed individually. Values regarding heat loss and exergy destruction have been presented for each equipment. The results confirmed that the condenser was the main source for energy loss (about 67%), while exergy analysis revealed that the boiler contributed to the largest percentage of exergy destruction (about 84.36%) which can be reduced by preheating the inlet water to a sufficient temperature and controlling air to fuel ratio.
Energy And Exergy Analysis Of Fully Condensing Steam Turbine At Various Steam Load Condition
2013
The power is very vital factor for development of any nation. Energy resources are limited in stock and its present consumption rate is in increasing trend. There fore energy efficiency and energy conservation are prime important. More over the technology largely used today to produce electricity from coal causes significant negative environmental impacts. Energy and exergy analysis are used to analyse the performance of thermal systems. Energy analysis deals with quantity aspect whereas exergy an alysis deals with quality and quantity aspects of energy. Exergy analysis focuses on magnitude and location of energy loss. In this analysis energy efficiency, exergy destructions, exergy efficiency and turbine heat rates are evaluated at 40%, 50%, 60%, 70 % and 80 % Maximum continuos rating condition of steam turbine. Analysis shows that operating turbine at 80 % MCR attract plant heat rate improvement by 1356.72 kJ/Kwh, which reduce environmental CO2 emission by 1907.79 kg/h, SO2 emissio...
Exergy analysis of steam condenser at various loads during the ambient temperature change
2020
The paper presents an exergy analysis of steam condenser at three different loads and in the ambient temperature range between 5 °C and 20 °C. An increase in the condenser load and increase in the ambient temperature resulted with an increase in steam condenser exergy destruction (exergy power losses). At low load, condenser exergy destruction is for the order of magnitude lower if compared to middle and high condenser loads. Decrease of the condenser load and decrease of the ambient temperature resulted with an increase in condenser exergy efficiency. The highest steam condenser exergy efficiencies are obtained at the lowest observed ambient temperature of 5 °C and amounts 81.47 % at low condenser load, 76.10 % at middle condenser load and 74.54 % at high condenser load. From the exergy viewpoint, the optimal condenser operating regime is low load and the lowest possible ambient temperature.
Effect of key parameters on thermodynamic and thermoeconomic performance of steam power plant
The first law of thermodynamics is a useful tool for thermodynamics processes analysis. The exergy analysis of a conventional steam power plant was done. This analysis is based on first and second law of thermodynamics. In the present paper, a conventional steam power plant was investigated using a thermoeconomic analysis. Having done this analysis the inefficient components of a steam power plant cycle was identified. In this analysis, it was assumed that the cycle components are adiabatic and the potential and kinetic terms of exergy were negligible. The exergy analysis combined with the economical aspects. These aspects include capital investment cost, fuel cost and operating and maintenance cost for evaluation of final cost of product. According to this calculation exergy destruction cost of each component in the cycle and their role were evaluated. Based on these results the effect of the component efficiency on the final cost of the product and performance revealed. Effect of main steam temperature, reheated temperature, condenser pressure and number of the feed water heaters on cycle performance and final electrical power cost were also determined.